I think what I love most is the composition of the image in general (symmetry makes me happy!). Captain Marvel's covers have always excelled in simplicity, usually just putting Carol in a cool pose that shows off her strength, both physical and personal. Incorporating that idea with the pleasing parallel lines gives this image a feeling of motion that not only gets you pumped to crack open the issue, but also gives the image a sense of epicness that other covers have lacked.

But really, it's Bellaire's colors that make this cover what it is. Using the blacks of space to mesh with Carol's costume adds to the intricacies of the image, making it far more interesting than if it were to be Captain Marvel's usual navy blue costume, but also adds to the cover's simplicity which is ultimately what makes it so attractive. In print, the black levels of the background and the costume are much closer than they appear in the image above, and it's gorgeous.